14 C.F.R. § 27.151 Flight controls.
Title 14 - Aeronautics and Space
(a) Longitudinal, lateral, directional, and collective controls may not exhibit excessive breakout force, friction, or preload. (b) Control system forces and free play may not inhibit a smooth, direct rotorcraft response to control system input. [Amdt. 27–21, 49 FR 44433, Nov. 6, 1984]
Title 14: Aeronautics and Space
PART 27—AIRWORTHINESS STANDARDS: NORMAL CATEGORY ROTORCRAFT
Subpart B—Flight
Flight Characteristics
§ 27.151 Flight controls.